MCS260B
CORNERSTONE 260B MONOCHROMATORS
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9.2 FILTER WHEEL
The Cornerstone 260B is capable of controlling an optional filter wheel, Models USWFW-100 or 74010. It
is also able to interface with the motorized filter wheel included with Oriel’s APEX2 light sources. These
filter wheels hold up to six 1-inch [25.4 mm] diameter filters. Neutral density filters can be used for
intensity adjustment. Order sorting filters may be installed to block higher order diffraction.
The filter wheel can be mounted to the male flanges of the monochromator slits or slit holders. The filters
are mounted external to the monochromator. Thus, the refractive index and thickness of the filters do not
significantly affect the focal distance to the collimating mirror inside the monochromator. With internal
filters, this distance would be different for every wavelength and every filter and would therefore adversely
affect resolution. The Cornerstone 260B is designed and manufactured to have errors of only a fraction of
a millimeter in the focal distance. Positioning the filters externally, usually before the input slit, has only a
slight effect on the light throughput. Since the slit acts as a secondary source, the focal distance is not
affected.
Figure 27: Model USFW-100 Filter Wheel.
Make sure to turn power off when connecting or disconnecting the filter wheel.
